The present invention relates to fittings for connecting electrical cables and flexible conduit to electrical panels and junction boxes.
The intention of the invention is to make an improved fitting that allows easier insertion of the electrical cables into the trailing end of the fitting and into the electrical panel or junction box at the same time. Historically, armored cable (AC) or metal-clad cable (MC) has been connected to a panel by a tubular fitting including a leading end having a threaded nose and a trailing end having a lateral screw mounted laterally through the fitting wall. Alternatively, a set of strap and screws were attached to the trailing end. The threaded nose was inserted into an aperture in the panel and a locknut tightened thereon secured the fitting to the panel.
AC or MC cable was then inserted into the trailing end and the lateral screw or the strap screws were tightened to secure the cable to the fitting. It is important to have secure grounding and since the fitting is made out of metallic material it creates a good electrical continuity (grounding) between the electrical panel and the cable.
Typically wiring a construction project electrically, whether it is a building or factory, requires electrical contractors to make hundreds to thousands of such individual connections. Moreover, such installation necessitates using tools to achieve a secure connection, including a wrench for the lock nut and a screw driver for the laterally mounted screw. Therefore, it should be appreciated that completing all of these connections can be very time consuming, since contractors usually use such tools on each connection.
Recently, several types of snap engagement fittings have been introduced as a means of connecting cables to electrical panels and junction boxes in order to reduce the time and effort required for installation of fittings in electrical wiring. Although using such snap engagement fittings eliminates the use of tools for installation, they typically require substantial effort to snap them on the junction box or panel.
Furthermore, if there is a need for a retrofit or disconnection of the fitting, the contractors have no choice but to use tools to remove the snap engagement fittings and that, in turn, also involves substantial effort and force.
Therefore, what is needed is a fitting for securing electrical cables to the panel or junction box of a type that does not require the use of any tools for installing or removal, of either the leading or trailing end, and that allows the leading end to connect quickly and securely to the electrical junction box and the cable to be securely fitted into the trailing end. Such a fitting would vastly reduce the time and effort involved in installing or removing electrical cables in a structure's wiring. The desired fittings must be designed to work with standard electrical panels, boxes, housings, and the like, while allowing quick and easy connection through standard size knock out apertures.
The present invention offers a quick connect fitting for an electrical panel or junction box that requires no tools for connecting or removal of the fitting. Moreover, it needs much less effort and force for installation or removal compared to the existing snapping fittings. Due to its unique design, there are large contact areas between the electrical panel or junction box, the fitting, and the cable jacket that in turn result in very good electrical continuity or grounding.